1. Field of the Invention
The present invention generally relates to a database system having a plurality of nodes (terminal devices) coupled together via a communication network. More particularly, the present invention is concerned with a database system in which each node can use data storage devices stored in other nodes.
2. Description of the Related Art
A conventional distributed database system has a host device and a plurality of nodes controlled by the host device. Each node has its own data storage device. A conventional database system is designed so that each node can access only its own data storage device under the control of the host device. If such a data storage device is filled with data (files), the corresponding node cannot use its own data storage device. Thus, the storage capacity must be extended so that a new data storage device is connected to the node having the overflowed (i.e., filled) data storage device. As a result, the entire data storage capacity of the conventional database system cannot be used efficiently.